This section is intended to introduce the reader to various aspects of the art that may be related to various aspects of the present invention. The following discussion is intended to provide information to facilitate a better understanding of the present invention. Accordingly, it should be understood that statements in the following discussion are to be read in this light, and not as admissions of prior art.
Atmospheric Monitoring Systems, herein after referred to as AMS, and their requirements are thoroughly described in The Mine Safety Health Administration's 30 CFR § 75.351.
http://www.msha.gov/30CFR/75.351.htm
Historically, AMS consisted of gas monitors connected over a hardwired network all communicating to a central area as described in the above requirement in section (b)(1). As the mine expanded and additional monitors were needed, lengths of cable were added to facilitate communications and power to new monitoring locations. As technology progressed, wireless and battery powered solutions became available. Extensive lengths of cable providing data and power were no longer needed. Mines now have the option of running a hardwired system or a hybrid of both hardwired with wireless. This becomes especially effective when the mine monitoring requirement consists of both permanent and temporary monitoring needs. Areas along the beltways are typically unchanging and are best suited for hardwired monitoring where developing areas of the mine are better suited for a wireless/battery powered solution. Aside from the existing hardwired network, a wireless communication network is still needed to transmit data from the wireless monitors to the designated central area. This could be served with a device that acts as an access point for the wireless monitor data to enter the existing hardwired network or an entirely separate true wireless network such as Strata Products Worldwide, LLC's CommTrac system.
As taken from section (c)(2) of the above requirement, an AMS must have the ability to “Automatically provide visual and audible signals at the designated surface location when the carbon monoxide concentration or methane concentration at any sensor reaches the alert level as specified in § 75.351(i). These signals must be of sufficient magnitude to be seen or heard by the AMS operator.”
The detail of importance in this section is the mention of “methane”. Traditional AMS hardwired systems offer methane monitoring but only in the 0-5% by volume range using catalytic bead technology. Methane concentrations above 5% will cause catalytic technology to be permanently damaged. In the event of a disaster and mine ventilation is lost, methane levels can easily exceed 5% concentration. Existing technology cannot provide atmospheric information that is critical during rescue efforts. No wireless or hardwired option exists to fulfill this need. Furthermore, the available wireless gas monitoring devices only offer carbon monoxide as a detectable gas and only in the 100 PPM maximum range.
As taken from section (c)(4) of the above requirement, an AMS must have the ability to “Automatically provide visual and audible signals at all affected working sections and at all affected areas where mechanized mining equipment is being installed or removed when the carbon monoxide, smoke, or methane concentration at any sensor reaches the alarm level as specified in § 75.351(i). These signals must be of sufficient magnitude to be seen or heard by miners working at these locations. Methane signals must be distinguishable from other signals.”
Traditional AMS hardwired systems offer this ability through a hybrid monitor/alarming unit although no wireless options for this requirement exist currently. Mines are often forced to run a separate control network if using a wireless monitoring solution to satisfy the section alarming requirement.
Similar to mines, oil and gas rigs need to monitor the atmosphere for dangerous levels of various gases without the need of cables and wiring cluttering the rig. In places such as oil and gas rigs, there is also the risk of dangerous gases and the need to monitor the atmosphere for these dangerous gases. Typically, gas monitors were connected by cabling and wiring throughout the rig has been used to monitor dangerous gases on a rig. The presence of all of these cables and wires distributed throughout a rig creates the problem of properly organizing and positioning the cables and wires so they do not interfere with the operation of the rig nor can be damaged so that connection is lost with the monitor during operation. If connection is lost with a monitor, then the monitor as well as the entire length of the cable or wire that connects the monitor to a remote station for monitoring must be examined to correct the loss of communication with the monitor. Such cabling and wiring could extend quite a long distance and be located in difficult positions to examine and can become a significant issue to correct.
In addition, in a mine, it is important to be able to track and communicate with a miner in ideally the most unobtrusive way possible. Besides the mine environment being a dangerous place in and of itself, the more equipment a miner carries, the more difficult it is for the miner to perform his functions and move through the mine. What is desired is a simple way to alert a miner of a dangerous or emergency condition, as well as for the miner to inform a remote station of the miner's condition and the miner's location.
To further provide for the safety of a miner, the miner is required to carry a light, such as a cap lamp that the miner wears on his head, as well as is required to be tracked in the mine, and also be protected from contact with machinery so as not to be injured by the machinery by accidentally contacting the machinery during operation. The latter protection is afforded with the use of a proximity device carried by a miner and proximity sensors positioned on machinery which, when determining that a proximity device carried by a miner is within a predetermined location of the proximity sensor, the machine is turned off so the miner is not injured. As the light is already required to be carried by a miner, and the proximity device is commonly carried by a miner, it would be desirable to combine tracking with these functions since they are already present on the miner.
To provide communication to and from the miner to inform the miner of important information or to track the miner or to enable the miner to communicate with the remote station, communication networks are critical throughout the mine. Since the mine is a very difficult environment for communication networks, redundancy, as well as data networks that ideally work best to transmit data, and voice networks that ideally work best to transmit voice bidirectionally, in which also can transmit data, and work in combination are desired.